A Beyond Pesticides
Factsheet

While communities
have good intentions, many existing policies and programs may be dangerous
to children, adults and wildlife and inadequate by relying too heavily
on spraying pesticides to kill adult mosquitoes.

NOT ALL MOSQUITOES
CARRY WEST NILE VIRUS

There are 175 different
species of mosquitoes in the U.S. and only a handful of those are vectors
for disease. Only adult female mosquitoes bite and require blood meals;
males feed on flower nectar.

Mosquitoes go
through four stages in their life cycles – egg, larva, pupa, and
adult. The complete cycle can take as little as four days or as long
as one month, depending on the temperature.

West Nile virus
(WNv) and St. Louis encephalitis are primarily associated with the Culex
mosquitoes.

Adult Culex females
live between 2-4 weeks, depending on climate, species, predation, and
a host of other factors. Culex mosquitoes are generally weak fliers
and do not move far from their larval habitat, although they have been
known to fly up to two miles. High bite rates usually indicate breeding
areas are nearby.

Mosquitoes are
most active at 80°F, become lethargic at 60°F, and cannot function
below 50°F.

THE REAL THREAT
OF WEST NILE VIRUS

Less than one
percent of those infected with WNv will develop severe illness, according
to the Centers for Disease Control. The vast majority of people (about
80%) who become infected with WNv will show no symptoms and never become
sick. Some 20% may experience mild flu-like symptoms within 3 - 15 days.

Brian Rogers, D.O.,
MPH, City of Fort Worth Health Authority states, “The risk of
becoming seriously ill and dying from West Nile is extremely minimal.
Fewer than 1 percent of mosquitoes in areas where the virus has been
found actually carry the virus.”

The U.S. Fish and
Wildlife Services states, “Contrary to media descriptions of 'the
deadly West Nile virus,' [it] is rarely fatal in humans. Less than one
percent of people who acquire the disease will experience severe illness.
Within this small proportion, the fatality rate is about 3-15%.”

Risk for severe
illness is most closely correlated with increasing age and a weakened
immune system. From 2001 to 2003 there was a drop in the average age
of WNv cases (which include flu-like symptoms), however the median age
of fatal cases has not dropped. The rise in cases in younger people
is probably due to the heightened detection of milder WNv cases.

A person who has
been infected with WNv may have life-long immunity even if they show
no symptoms.

PESTICIDE
SPRAY PROGRAMS ARE INEFFECTIVE

According to the
Centers of Disease Control and Prevention (CDC), spraying adulticides,
pesticides intended to kill adult mosquitoes, is usually the least efficient
mosquito control technique.

Adulticiding programs
spray pesticides indiscriminately and do not get at the mosquitoes until
they have matured. They also do not restrict, control, or prevent mosquitoes
from carrying WNv or continuing to breed.

Close to 99.9 %
of sprayed chemicals go off into the environment where they can have
detrimental effects on public health and ecosystems, leaving 0.10% to
actually hit the target pest.

Mosquitoes develop
resistance to pesticides over time, rendering the chemicals ineffective.
A 2003 study finds that mosquitoes carrying West Nile virus and malaria
developed resistance to organophosphate and carbamate insecticides as
a result of a single genetic mutation.

After Hurricane
Floyd caused a surge in mosquito populations in Florida, state officials
took bite counts before and after widespread aerial spraying and found
that mosquito populations surged back to pre-spray levels within three
days of the treatment.

Programs usually
measure post-spray mosquito populations within 3-5 days. Most do not
retest the area to detect the resurge in populations to pre-spray levels
after 7 or more days.

In 2003 the city
of Boulder, CO did not adulticide and showed an 80% reduction in mosquito
populations and lower rates of serious illness per population than surrounding
cities where adulticiding took place.

Despite high mosquito
counts and large percentages of infected birds, Shaker Heights, Ohio
refused to adulticide like its neighboring cities in Cuyahoga County.
2002 results showed the county had 219 cases of WNv with only 2 cases
occurring in Shaker Heights.

The counties of
Goshen and Plate, WY rely heavily on adulticides and in 2003 counted
80 WNv cases, 8 fatalities and 77 cases, 3 fatalities, respectively.
Their neighbor Cheyenne, with 2 times the population and 3 times the
landmass, used only larvicides and had 20 cases of WNv and 1 fatality.

Synthetic
pyrethroids, which include resmethrin (Scourge) and sumithrin (Anvil), are adulticides patterned after
pyrethrum, yet have been chemically engineered to have greater toxicity
and longer breakdown times. Almost all synthetic pyrethroid mosquito products
use synergists like piperonyl butoxide (PBO), a petroleum distillate,
which increases potency and compromises the body's ability to detoxify
the pesticide. Petroleum distillates are carcinogenic and linked to birth
defects and other illnesses. Animal studies have shown children to be
more sensitive than adults and that exposure may inhibit neonatal brain
development. Pyrethroids are highly toxic to fish and honey bees, even
in low doses.

Symptoms of exposure
include: dermatitis and asthma-like reactions, eye and skin irritation
and flu-like symptoms. Synthetic pyrethroids are endocrine disruptors
and have been linked to breast and prostate cancer. People with asthma
and pollen allergies should be especially cautious. Exposure has resulted
in deaths from respiratory failure. Breakdown times range from a few hours
to several months.

PESTICIDE
SPRAY PROGRAMS AFFECT PUBLIC HEALTH AND THE ENVIRONMENT

The U.S. EPA warns,
“no pesticide is 100 percent safe.”

National Research
Council found that pregnant women and children have a greater risk of
getting sick from pesticides.

In NYC in 2000
more people were reported to have gotten sick from pesticide exposure
from spraying than from WNv.

Adulticides kill
beneficial insects and natural mosquito predators, such as dragonflies,
damselflies, and beetles, potentially increasing local populations of
mosquitoes.

Mosquitoes that
survive pesticide sprays may become resistant, longer-lived, more aggressive,
and have an increased prevalence of the virus within their bodies.

Brian Rogers, Ft.
Worth Health Authority states that, “Spraying for mosquitoes would
harm more people than it would help.”5

New York State
Department of Health states that adverse outcomes during or after an
aerial or ground spraying of adulticides might include acute asthma
attacks, other respiratory problems, and/or dermatological problems.

Synthetic pyrethroids
are neurotoxic and have been linked to cancer. People (particularly
children) with respiratory problems, such as asthma, are especially
vulnerable to these pesticides and will suffer disproportionately from
exposure.

Washington, DC
cites both lack of efficacy and asthma concerns among reasons for its
no-spray policy.

In 1999, malathion
spraying was found responsible for the death of over 2,000 fish on Staten
Island.

On June 26, 2001,
The Post Star reported that 37 young ball players and spectators at
a softball game in upstate New York were hospitalized after being poisoned.
According to Moreau Emergency Squad Captain Andre Delvaux, a pesticide
containing the organophosphate malathion, was being sprayed to control
potential WNV carrying mosquitoes near the baseball field while a game
was in progress.

Studies published
in 2001 by Duke University researchers found that combined exposure
to DEET (N,N-diethyl-m-toluamide) and permethrin could lead to motor
deficits and learning and memory dysfunction.

In 1998, EPA rejected
“child safety” claims for DEET products and required all
such claims to be removed from existing products.

On June 3, 2001
the Associated Press reported that in New York more than 50% of dead
crows collected in response to West Nile virus died from exposure to
pesticides and lead, rather than from West Nile virus.

In 2000, five spray
operators filed a complaint against New York City claiming they became
sick due to improper training and prolonged exposure while spraying
adulticides.

A 1999 Mount Sinai
School of Medicine study examined four pyrethroid pesticides, including
sumithrin, and concluded, “[E]ach pyrethroid compound is unique
in its ability to influence several cellular pathways. These findings
suggest that pyrethroids should be considered to be hormone disruptors,
and their potential to affect endocrine function in humans and wildlife
should be investigated.”

Commercial fishermen
in Maine filed a $125 million lawsuit claiming that the dramatic decrease
in the lobster harvest was due to the spraying of an adulticide containing
malathion.

Reports of inappropriate
and/or illegal spraying practices are common. Children are known to
follow spray trucks for entertainment. Other practices include fogging
during daylight hours, during wind speeds higher than 10 mph, and in
no-spray zones. Proper integrated pest management is often ignored.

Organophosphates,
which include malathion (Fyfanon), naled (Dibrom) and chlorpyrifos (Mosquitomist), are a highly toxic class
of pesticides that affect the central nervous, cardiovascular and respiratory
systems. Symptoms of exposure include: numbness, tingling sensations,
headache, dizziness, tremors, nausea, abdominal cramps, sweating, incoordination,
blurred vision, difficulty breathing, slow heartbeat, unconsciousness,
incontinence, convulsions and fatality. Some organophosphates have been
linked to birth defects and cancer. Breakdown times range from a few days
to several months, depending on conditions.

SAFE &
EFFECTIVE MOSQUITO MANAGEMENT STRATEGIES

The first step
in managing mosquitoes is personal protection and source reduction.
Use natural-based repellents and wear long-sleeves and pants if outside
during dawn and dusk to avoid getting bitten

Remove all potential
breeding areas – any place with standing or slow-moving water.
Remove, puncture or regularly drain all water-retaining objects such
as tin cans, buckets, holes in trees, clogged gutters and down spouts,
old tires, birdbaths, trash can lids and shallow fishless ponds. Fix
dripping outside water faucets and sprinklers. Monitor ponds and sources
of water regularly for signs of mosquito larvae.

Maintain window
and door screens, and keep closed around dawn and dusk when mosquitoes
are most active.

Stock permanent
water pools or ponds with fish that eat mosquito larvae and pupae, like
Gambusia holbrooki.

Least-toxic larvacides
(killing mosquitoes in the larval stage) allow control measures to be
targeted and kill mosquitoes before they become active, biting adults.

Bascillus
thuringiensis var. israelensis (Bti) is one of most effective and
least hazardous biological larval controls. It is a bacterial strain
that, when sprayed or dropped into larval pools, is ingested by feeding
larvae and kills them. (Mosquito DunksTM can be bought at local garden
stores or on-line. They are safer for birdbaths, ditches, tree holes,
roof gutters, etc. – anywhere water collects.)

Vegetable based
horticultural oils are effective in killing larvae in water and sinking
egg rafts on the surface, but can also kill non-target organisms including
some mosquito predators that breathe from the surface.

Mosquito traps
and attractants are effective, though different levels of success have
been reported. These machines send out plumes of carbon dioxide to attract
mosquitoes that are then sucked in and killed.

The CDC recommends
the formation of local WNv community task force with representatives
from government, civic, business, health, and environmental sectors
to achieve buy-in within the society.

COMMUNITIES
THAT HAVE ADOPTED SAFER MOSQUITO AND WNV MANAGEMENT PROGRAMS

Lyndhurst,
Ohio, passed a landmark ordinance in 2003 prohibiting the spraying
of pesticides for WNv. During a Task Force sponsored forum, a panel
of experts discussed the hazards and low efficacy of adulticides. The
Council stated, “[T]here is substantial belief that the more effective
way of controlling the mosquito populations is by larvacide treatment
and thorough education...” Concluding that, “[T]he dangers
of WNV are minimal and affect a very small segment of the population
and that the long-term health and environmental risks of spraying with
synthetic pesticides poses a much greater risk.” South
Euclid, Ohio passed a similar ordinance, the second of its
kind in the country, in July 2004.

Washington,
DC health officials continue their no-spray policy stating
that pesticide spraying is inappropriate in a heavily populated area
with asthmatics. Instead, officials focus on larval control and pubic
education, with education materials distributed in four languages. The
Department of Health is also implementing a Tire Round-Up program for
residents to discard old tires, a major breeding site for mosquitoes.27

In York
County, Virginia, officials distribute the mosquito eating
fish, Gambusia holbrooki, to residents in order to decrease pesticide
use for mosquito control. Several thousand of the fish have been bred
by the county's fishery as part of its mosquito prevention program.

In Dallas,
Texas, the City Council's Health, Environment and Human Services
Committee adopted a mosquito control plan in 2003 that calls for more
public education and allows the use of pesticide sprays only as a last
resort and upon approval of the pertinent council member.

Ft. Worth,
Texas has not sprayed for mosquitoes since 1991. In 2003, Ft.
Worth had 3 WNV cases and no deaths. Brian Boerner, Director of Environmental
Management, states, “the spraying of chemicals also has the potential
of contaminating our waterways, killing the beneficial fish and organisms
that feed on mosquito larva, adding harmful volatile organic chemicals
to the atmosphere-a precursor chemical to ozone formation-and providing
a potential inhalation or ingestion hazard to residents.”

Nassau
County, New York joins others in using predacious fish in hard
to reach salt-water marshes.

Marblehead,
MA has a WNV Response Plan that requires a town hall meeting
before any adulticides are used (and only if there's been a locally-acquired
human death).

In 2003, Boulder,
Colorado focused on larviciding, surveillance and public education
without the use of adulticides and offered free WNv information workshops
for neighborhood groups and distributes free samples of Mosquito Dunks,
a least-toxic larvacide product, for use in stagnant water.14

In preparation
for WNv, Lane county, OR have an easy to read public
educational flyer that is put in local
newspapers and distributed with utility bills early in the season.

In 2003, Seattle,
Washington adopted an Integrated Pest Management Plan for Mosquito
Control, which
identifies public education, personal protection, and breeding source
reduction on public property as, “…the most effective and
appropriate techniques for the City to use.”